1. Field of the Invention
The present disclosure relates to a manufacturing device of a film patterned retarder for a three dimensional display devices. Especially, the present disclosure relates to a manufacturing device for a film type patterned retarder in which the left polarization exposure and the right polarization exposure are performed at different areas, respectively, using the single photo aligning step.
2. Discussion of the Related Art
Recently, thank to the advancement of the various video contents, the display devices which can selectively reproduce 2D images and 3D images are actively developed. For reproducing the 3D images, the display uses the stereoscopic technique or the autostereoscopic technique.
The stereoscopic technique uses the binocular parallax caused by the human two eyes apart from each other. There are typically two types; one is the glasses type and the other is non-glasses type. For the glasses type, the display device displays the left eye image and the right eye image in different polarization directions or in time division manner. The observer can enjoy the 3D images using the polarization glasses or the liquid crystal shutter glasses. For the non-glasses type, an optical plate such as a parallax barrier for separating an optical axis of the parallel image between the left eye and the right eye is installed in front of or behind of a display screen.
In the 3D display system using the glass type stereoscopic technique, for one example, the polarization glasses type includes a display panel attaching the polarization selecting element such as the patterned retarder on its surface. The patterned retarder is used for setting the polarization directions of the right eye image and the left eye image represented at the same time on the display panel in different from each other. In the polarization glasses type 3D display system, the viewer shall wear the polarization glasses for enjoying the 3D images. The left eye image can be reached to the left eye of the viewer through the left filter of the polarization glasses while the right eye image can be reached to the right eye of the viewer through the right filter of the polarization glasses.
On the other hands, in the 3D display system using the shutter glasses type stereoscopic technique, the display panel represents the left eye image and the right eye image in different time period. In the shutter glasses type 3D display system, the viewer shall wear the shutter glasses for enjoying the 3D images. During the left eye image activation period, the left eye shutter of the shutter glasses is opened only, while the right eye shutter is opened during the right eye image activation period.
As the shutter glasses type 3D display system does not need to have the polarization selecting element attached on the display panel, the price of the display panel is not expensive. However, as the shutter glasses are very expensive, the cost for configuring the whole 3D system is expensive. In the aspect of the 3D video quality, as the shutter glasses type uses the time division method in which the left eye image and the right eye image are represented in different time periods, it cannot be free from the problems of the flickers and the 3D cross-talks.
On the contrary, as the polarization glasses type has to have the polarization selecting element such as the patterned retarder, the price of the display panel shall be expensive somewhat. However, as the polarization glasses type uses the polarization glasses which are much cheaper than shutter glasses, the cost for configuring the whole 3D system is cheaper than that of the shutter glasses type. Furthermore, in the aspect of the 3D video quality, the left eye image and the right eye image are represented at the same time frame and they are divided line by line. Therefore, it may have a lower density than that of the shutter glasses type, but it has the less problem of the flickers and the 3D cross-talks than that of the shutter glasses type.
There are typically two types of the patterned retarder; one is the glass patterned retarder (or “GPR”) in which the patterned retarder is formed on the glass substrate and the other is the film patterned retarder (or “FPR”) in which the patterned retarder is formed on the film substrate. Recently, the film patterned retarder is mostly used because it is thinner, lighter and cheaper than the glass patterned retarder.
According to the currently used method, to make the film patterned retarder is very difficult and it is hard to configure the manufacturing devices because at each tiny area corresponding to the pixel area shall have individual pattern of the patterned retarder. Furthermore, in order to make a large area film patterned retarder, it is required to configure expensive and complex manufacturing devices. Therefore, nowadays, it is required to develop a simply structured manufacturing device for the film patterned retarder using the simplified manufacturing steps.